The Promise
by loptr166
Summary: Thor is shocked that Loki has vanished and not returned to Asgard with him. Instead, the trickster finds himself at the mercy of a tyrant with an unquenchable thirst for death. What will Loki be willing to sacrifice to get what he wants? Takes place post Avengers *Warnings- non-con, dub-con, slash, thorki, violence, explicit sexual content, brief femloki, no-beta*
1. Chapter 1

NC17 (slash, somewhat AU, sexual content, violence, non-con/dub-con, pseudo-incest, no beta) Pairings: Thor/Loki, Thanos/Loki

Additional warnings: There is a scene where Loki shapeshifts briefly into a female.

—

PT. 1:

Loki wakes to himself rapidly descending from a great altitude; there is nothing to break his fall. All he sees are the vestiges of a dark, barren wasteland greeting him below.

It's inevitable, his beaten body is haplessly deposited onto a floor of dirt and rocks. The crushing impact forces any trace of air to vacate his lungs and as he attempts to cry out in pain, only silence persists. The cursed gag remains fastened to his mouth.

A mist of fine dust rises over the ground, followed by his fall. Throbbing pain saturates every muscle, ligament and bone in his body, making his eyes brim with tears. He tries hacking granules of dust that he inhaled, to no avail. The muzzle, strapped viciously to his mouth, proves to be a greater burden than he had ever imagined. And with his wrists fettered, his movements are minimal and constrained. The manacles, secured to him, are relentless in their power, preventing him from conjuring any form of magic. Even if he only means to heal himself.

Eventually, Loki comes to rest on his back, limbs outstretched. He breathes profusely from his nose, gasping desperately despite the gag. Ravished by physical agony and incapacitated, he blinks up at the sky to see a vortex of swirling grey clouds quickly dissipating above him. The journey to Asgard, by the looks of it, has abruptly come to an end. For it is not Asgard he finds himself in; it is a world that is frighteningly familiar.

Without warning, a bone-chilling wind appears, sweeping through the landscape, blowing heaps of dust with it. How ironic, he thinks, it may be his Jotunn heritage that will prolong his life on this miserable planet. Prolong his suffering.

"_Welcome back._" A disembodied voice perturbs the air, gravely and undeniably masculine.

Loki perks his head up, distraught by what he believes to have heard. Was it Thor? He frantically looks around him, seeing nothing and no-one in his vicinity. Silence ensues afterwards and he concludes it may as well been a trick of the mind.

Just a gust of wind…He assures himself, content in that thought. No reason to question his sanity over something so trivial. His eyes lazily wander about his surroundings.

Still, why has there been no sign of Thor?

He remembers last taking hold of the Tesseract shortly before a column of energy seized them both from the Midgardian world. Their destiny was Asgard, but he was no where near Asgard and Thor was no where to be seen or heard.

Thor must have made it there. He determines, lying motionless on the ground, still in disbelief. This particular destination was likely meant only for him.

Loki wonders what Thor would think when he sees that his prisoner had not arrived by his side. Rumor would be that the Silver-tongue had escaped on his own volition. Or had Thor agreed to have him sent here as punishment? It suddenly occurs to him, fearing it may be true. To leave him here, withering away, alone.

It isn't long before the stench of Midgard permeating his filthy, tattered ensemble reaches him; he crinkles his nose with disgust. It is the stench of defeat. Sighing in dismay, he stares upward, transfixed on the fading clouds, suggesting the closure of the portal that had transported him to this world. It leaves behind a sunless sky, pitch black, interspersed by distant stars and galaxies.

"You have returned sooner than I would have liked." The same voice bellows.

Realization finally stirs him and he can feel a stab of terror deep within him. It hadn't been an illusion, after all.

Then, it dawns on him. This empty world had been the location where he unwittingly wagered his life on a promise and one with unspeakable torture should he fail to make good on it.

Dreading what lies ahead, he notices a sharp change in his breathing. He is not alone.

The voice he heard is not one he recognizes, but he believes it to be a principal commander of the Chitauri. Albeit, it lacks that shallow rasp that seems inherent to their specie. Loki rolls on his stomach and props himself up on his elbows, oblivious to pain as he struggles on shaking knees to make himself stand. The armor plating he wears is scratched and worn, hanging loosely against his body. The rest of his garb fairs no better, his leather surcoat and breeches are tarnished, beyond repair. He mindlessly pats his hands over the length of his attire, in a futile effort to rid himself of dirt that had clung to him.

"Let's have a look at you, shall we?"

The ominous words resonate on his back. Loki turns his head, peering over his shoulder. Unable to see much of anything, he listlessly staggers on his feet, turning to get a glimpse of the one addressing him.

Panning into view is the silhouette of a gargantuan being, seated over a solid mass of slabbing stone at the base of a terrace, too close for comfort. He appears to rest his arms over his knees, his body slouching forward as he surveys his company.

The alien figure is not comparable to that of any Chitauri anatomy known to him. It is significantly larger and distinctive.

Adjacent from there is a stationary pod in the distance. Evidently crafted for space travel. There are two Chitauri soldiers that stand guard on each side of the pod, but seem indifferent to his presence.

His eyes drift back to the body perched nearby him, but he cannot distinguish the being's features due to the obscurity of this desolate world. This is coupled by the shadow of the terrace, casting over them. Loki stands in place, his shackled hands falling limply at his sides.

The rattle of the chain draws the stranger's attention, inviting his degrading remarks. "Not only have you returned without the tesseract, but they have mocked, bound and gagged you. A self-proclaimed god, but a travesty is all you are."

Loki willfully suppresses a rush of anger. Does this alien imbecile think it was to be so easy and predictable? He wonders, incredulously.

The being mocks him further, knowing his captive has no means to answer him, "What more could I have expected from a simple bastard?"

As cold as this world is, a dormant flame begins to seethe in Loki. It's infuriating and shocking all the same. _How is it possible?_ Does this alien truly know of his origins? He exhales audibly through his nostrils in retort, but he knows better than to hint at defiance. He must concede now and bide his time carefully. Yes, he would do better to play along with this creature than to compromise himself.

Without being asked, the trickster gracefully drops to one knee, bowing his neck subserviently to this being. Stray locks of dark hair fall out of order and shroud his pallid face as he adjusts himself over the uneven surface. He will put on an act if he must, but it will be for his own benefit. He faces the ground with eyes closed, simulating an act of submission to his utmost ability.

"Learning your place in the universe with such gratuitous urgency?" The being derides him. "Or perhaps, you have a talent at deceiving others by your actions, as well?"

His heart skips a beat, and his verdant eyes snap open in astoundment. He cringes at the prospect of just how much this being knows about him. Does his reputation as the alleged God of Mischief precede him this far?

"You may be asking yourself, how you got here. Well, don't let that occupy your mind." The being says, rising to his full height atop the slant rock. "Just a detour, if you will." He glances across the solemn horizon, appearing to admire the view from his vantage point. Stooping, he hurdles to the ground, mere steps from his quarry, landing with a resounding thud. Loki flinches, squinting his eyes while a cloud of dust fills the air.

As it settles, he spots a shadow moving steadily to his right. "There are far greater concerns for you, fallen prince." The large being announces, stepping out from the shadow of the terrace into the dim light of the stars. "Hereon, you will refer to me as your lord; _Thanos_. I am of the world known as Titan, as you may know." He pauses, head turned in Loki's direction. "Not that it has any pertinence to that of an Asgardian outcast."

It is _him_… Loki realizes.

It was he, who had commanded the Chitauri follow Loki's lead. He, who had bequeathed the scepter to Loki, so that he may deliver the tesseract in return. It was he, who Loki had failed. The trickster contains a primal fear goading him to flee. Instead, he forces deep, measured breaths as another drop of sweat streams down his forehead, pooling across the fringe of his gag.

Finally, the opportunity to see this tyrant with his own eyes presents itself. On bent knee, it only exaggerates the lord's height, but there is no doubt that he is large. Larger than Thor. He is of such stature, he resembles the bulk of that ferocious green monster that had bested him back on Earth. The former prince can only peer up at this creature, captivated by what he sees.

Thanos wears a cerulean body-suit that is matched to the bulging contours of his muscular physique and what appears to be a helm fitted over his head. There are trims on his helm lined in a gold chrome, that mold to his face. His skin is a stale, shade of purple and his broad, chiseled face is accented with a sinister grin. It is further pronounced by the jut of his rectangular jaw. What is most alarming are his eyes. They are as dark and empty as the void, showing nothing, no emotion, no life. Loki shudders and his gaze resigns to the ground again.

"Don't like what you see?" Thanos asks with a subtle cadence.

Loki strives to comprehend the gravity of his situation. He knows the heinous entity standing over him is one riddled with mystery and ambivalence. The only thing that is certain, is that he is an all-powerful demigod of sorts. Loki recalls the prattling and affairs of dignitaries from other worlds that would stop into Asgard by occasion. He knew only from stories told by them that Thanos, otherwise known as a god of death, stopped at nothing. He was ruthless in his endeavors and he would cut down anything or any foe standing in his way. His subordinates were equally fair game. The Aesir were quick to dismiss these tales; to acknowledge that such individual power existed beyond the realm would translate as a threat. And threats against the might of Asgard's kingdom were typically unheard of.

Nevertheless, this rumor, true or not, is not the only concern to him. He is accustomed to subordination and he has played the role well. What troubles him more is the potential that Thanos is as able to circumvent the schemes that Loki is so fond of contriving. Indeed, Thanos may be as formidable in mind as he is in body. He could not let his guard down, not for an instant.

Loki makes no gesture to answer him, he keeps his eyes down, focusing on a rock that lies conveniently in sight. It is dark as coal, with bright cross-hatches scarring its exterior. He would count them each, if that is all he could do to distract himself from this predicament and the likelihood that this mad lord would have him executed on a whim. For the trickster, this is also a test. Although, he has no means to convey his thoughts through words, he can still exhibit subservience to him. Perhaps this could generate the leniency that would spare him from death. At least, for now.

Thanos cocks his head down at Loki and scratches his chin thoughtfully. "I see…You and I both know where this is going, so I'll cut to the chase."

The Titan begins pacing slowly, circling the captive, as if in contemplation. Each pounding step rippling the ground beneath him. Loki holds his posture, unmoving and disciplined in spite of the nervousness plaguing him.

"Your incompetence will not go unnoticed. I've yet to decide on what punishment would be most appropriate." Thanos comes to a stop behind Loki's knelt form. Loki may not see him directly, but he perceives his presence. The tyrant emanates an aura of irrefutable power, raw and foreboding.

At the moment, he lives only because Thanos allows it. There is nothing to prevent him from doing away with the one who had promised him the tesseract and failed to retrieve it.

The chances that he will die at the hands of the Titan seem ever more likely. He wonders if betting his life on the assumed generosity of this alien despot had in fact been a good idea. This, however, is not the first time Loki has starred death in the face. And as before, he is given little choice; it's a chance he's forced to take.


	2. Chapter 2

NC17 (slash, somewhat AU, sexual content, violence, non-con/dub-con, pseudo-incest, no beta) Pairings: Thor/Loki, Thanos/Loki

Additional warnings: There is a scene where Loki shapeshifts briefly into a female.

—

PT. 2:

Numbness spreads through Loki. No one has shed tears in his absence, nor will they shed tears when he is gone. So, what incentive is there for him to shed tears of his own now? His mind goes blank in that moment and he makes his peace in knowing it will all be done with. The endless pain and tribulations. Gone.

In the aftermath of it all, he can't help, but think back on the events leading up to his capture. He feels his body perspire with ceaseless anxiety as he awaits imminent judgement. All while, in silence; he re-analyzes every noted miscalculation within a plan — a plan of his own making — guaranteeing him and his accomplices their share in victory. If only he had known the tenacity of his rivals. One of them being his former brother, Thor.

All his tedious plotting had been for naught because of their alliance. The 'Avengers'. How ridiculous...It was incomprehensible that they would ever find common ground. Apparently, that common ground involved his defeat.

Loki stops short of a grimace, he hasn't even the freedom to shape it to completion. This attachment, bearing on his mandible and intrusively between his lips was added for the sole intent of demeaning him. Subdued and on the brink of impending death, as he was again, he surrenders to the maelstrom brewing in the hollows of his mind.

* * *

In one instance, Loki would find himself overlooking the skyline of a majestic, Midgardian city. It was said to be called 'New York'. Tall structures scattered the horizon, like the towers of Asgard's palace. Pillars that once stood skyward, were now fallen and shattered by the unhindered assault of the Chitauri arsenal. It was a lot like a forest comprised of wires, glass and steel, gone up in smoke.

For creatures regarded so brash and uncivil, these mortals were nonetheless capable of impressive feats.

Loki stood menacingly on the outer rim of the Stark Tower's platform, arms extended in embrace. He couldn't help the smirk forming on his lips, nor deny the thrill he felt observing the nature of chaos overwhelm the city below. 'A morbid solace', was how he would describe it.

Brandished by elaborate and nearly impenetrable armor, along with his most prized asset, there was nothing to stop him. Not anyone, not Thor. This marvelous tool of conquest was bestowed to him by a nameless tyrant who ultimately had given Loki command of the Chitauri, as well. He held the scepter out before him, clasping both hands around the stem and visually examining the artifact adjoined to the upper shaft. The glowing, pulsing energy it manifested enthralled him. This was _his _to wield and _his_ to control. A weapon powered by the tesseract itself and he would not be precarious in its use. With this, he would carve a kingdom of his own.

...

Another rift in time, not long after.

Loki was now tracking Thor's hefty frame tread across that same platform. The elder god's electric blue eyes peered back at him behind long strands of golden hair that had fallen past his face. It was an unsettling scrutiny emphasized with Mjolnir fastened in his grip.

This relic, Thor possessed, unnerved Loki to no end. A solid testimony of his former brother's fortitude and brute strength. The trickster hesitated and withdrew several steps, distancing himself from the burly warrior. Of course, it garnered him nothing. Thor hastened his pace in response.

Then, for a second, he felt that he'd left his body and beheld himself as an outsider would; reading the story of his life like a book.

_How bizarre it all was, and how far he transcended in such little time..._

The questions would come with no answers to follow.

_Why again had he come here? What precisely was he hoping to accomplish...?_

_And mostly, why was his beloved Thor running towards him so fiercely, his face twisted with scorn?_

He could not fathom the seriousness of the crisis at hand, not in this light. It was almost comical to him.

The moment of introspection did not last long, Loki was alerted by the quake of his current rival's heavy steps approaching. This was no day-dream. He could feel his muscles aching and see the cool vapor of his breath against the warm, stagnant air. A stark reminder of his Jotunn biology.

Beads of sweat dotted his brow and desperation mounted. He lied in wait for Thor, luring him within proximity, then strained his shoulders against the weight of his armor, swinging the razor-end of the scepter at his foe's temple. It was delivered with calculated, deliberate accuracy, but as expected, the feral scion of Odin had foreseen it.

As if by instinct alone, Thor avoided the encounter with surprising grace. He angled his torso, leaning from the scepter's lethal edge. It would have grazed him had it not been for a mere fraction in time, separating them and permitting the scepter veer beyond risk. Now, the blade was swinging away from its target; making Loki susceptible to attack.

They both knew this and Thor was swift to exploit it. Without further ado, he looms upon his younger brother, raising Mjolnir high, threatening to destroy the silver-tongue with a single strike. But it never came.

Loki understood that Thor was no amateur to combat. He was rich with untold years of battle and he was again faced with the humiliating fact that his would-be brother had spared him.

...

Fast forward only moments later and they were entwined in what seemed to be an unending power-struggle.

Thor made progress, containing him. He grasped at his brother's arms, stilling him. He had no desire in hurting him, he only wished to see Loki as he once did. Revive him from whatever power inveigled him. Meanwhile the trickster frolicked, making every effort to push him away.

"It's too late to stop it!" Loki cried out in rebuttal to his brother's earlier assessment. A world to rule or not, maybe it wasn't what he had wanted, and he didn't care. For the time being, he could only concentrate on his steps as he was pushed towards the end of the platform, forcing him to brace against the tower's outer walls. There was no where else to go.

"No." Thor contended, evoking his words with as much sincerity as he could muster, "We can…..Together."

Unable to find the proper words to retaliate with, Loki flustered, his face visibly ridden with shame. It was an unusual occurrence and he lacked the immediate strength to neglect the manner in which his one-time kin had looked him in the eyes. A humble plea to reunite them; he would have never expected his brother's forgiveness, so soon and resolute.

Foolish oaf. He thought with pity. After all that had transpired, why did he still believe…?

And to his astonishment, the hardened resolve he guarded so adamantly broke apart by only the virtue of Thor's words, a single tear escaping him. It trickled down his cheek, confessing more than his tongue ever allowed.

But it _was_ too late for the _liesmith_. How could Thor not know this? Did he expect him to surrender and willfully hand over his sovereignty to Asgardian rule? A sure death sentence awaiting him in the end.

No, granting Thor the opportunity to witness the fragility he layered beneath the many masks he wore was regretful. The taste of triumph was much too close for Loki, he could savor it and he would not relinquish it now.

Apart from personal glory, was the contingency of failure that roused the silver-tongue from his lamenting; the fear it created, reigniting him with undue purpose.

_How dare he?_...That arrogant brute; did he truly expect forgiveness in return? _Never_...Loki vowed. Never again, would he offer this impostor of a brother another chance to capitalize on his weakness as he had done so many times in the past.

Undeterred and without consideration, he pierced Thor below the rib-cage with a hidden throw-dagger that he'd tucked away. He routinely veiled it under the sleeve of his bracer in the event that he'd actually need it. And he certainly did now.

"Sentiment..." Loki whispered to him absently, pressing the blade through a wall of armor and flesh. Contempt had taken root in him and his expression, placid before, stressed into a sneer.

Thor did not have the repeated fortune of thwarting this close quartered attack, just as Loki had hoped; nor had it been enough to critically damage him.

* * *

As sudden as the memory of that day appears to him, it fades back into a sea of darkness, leaving him to current matters...

On his knee, in the stillness of a somber, alien world, Loki is keen to the slightest sounds. Briefly, he listens to the pronounced, irregular beating of his heart. Then a rustling is heard behind him, and he is positive that Thanos will dispose of him like he were refuse.

Despite his outward disposition; he is grateful not having to face Odin, Frigga and the others. To be admonished and reminded of the disgrace he has become. He would have, undoubtedly, been brought before the council for treason. A crime worthy of death on its own.

Surely, Allfather must now regret ever taking him as his adoptive son and providing him a home in his kingdom. Perhaps, it would have been better to have left him there to his fate on Jotunheim; to die abandoned and unwanted. Has this not been his destiny, regardless?

Alas, he cannot deny fate now.

His lids grow heavy on his weary eyes, waiting on that final blow; be it a shattering hit to his neck, severing his vertebrae or better yet, an explosive reaction tearing him apart, into smithereens.

It startles him awake to hear the tyrant's daunting voice indulge him instead.

"Nevertheless, I may still have use for you, runt. For this reason alone, your meager existence will continue. In addition, I shall have your speech restored."

A cunning smile spreads on the Titan's face unbeknownst to the liesmith.

Loki senses the contraptions tied to his muzzle begin to loosen. The straps secured on either side seem to fall apart on their own, unraveled by some unseen force. He does not hide his shock. His eyes are wide, stunned to realize how easily this being has undone the bindings of the gag. The Titan's steps resume, until Thanos stands before him anew.

Gloved fingers snake below Loki's jaw, coaxing his head back and the muzzle is pulled away from his lips. He hears the clamor of the muzzle fall upon the ground, discarded.

The unyielding pressure around his mouth that had kept him in silence subsides gradually. He coughs hoarsely, clearing his throat. As he prepares to speak, Loki forces himself to concentrate on the face of his superior. His eyes warily greet the Titan's own. To his relief, he feels his mouth moving freely and once more, hears the soothing sound of his own voice. "Thank you..." He utters between ragged breaths. "...My lord."


End file.
